DreamWidth creates proxies for image links that are not secure (https), and this is for people who have set their browsers to prefer secure links. The Photobucket source is not a https link, so Dreamwidth made one. It gets interesting when the image is a dynamic countdown, like the one in this community sticky post. The image seen by people who prefer secure links is of the countdown clock at whenever it was when DreamWidth made the proxy, and so for them, the clock is stuck. (Probably not the greatest example at the moment as apparently whoever tends to the clock doesn't know when the next episode in question will air.)